Field of the Invention
The present techniques relate to a method for producing a Group III nitride semiconductor light-emitting device, which method can provide a flat light-emitting layer.
Background Art
Group III nitride semiconductor light-emitting devices each have a light-emitting layer which emits light via recombination of an electron and a hole. The light-emitting layer has a well layer and a barrier layer. The barrier layer has a bandgap greater than that of the well layer. Some semiconductor light-emitting devices have a multiple quantum-well (MQW) structure in which well layers and barrier layers are repeatedly deposited.
Thus, such a light-emitting layer generally has a plurality of deposited semiconductor layers. The semiconductor layers forming the light-emitting layer are preferably flat, since a favorable potential profile of a well layer is realized when the light-emitting layer has high flatness. In such a flat light-emitting layer, electrons and holes are more efficiently recombined in a well layer. That is, the higher the flatness of the light-emitting layer, the higher the luminance of the light-emitting device employing the light-emitting layer.
In order to form a flat light-emitting layer, there have been developed some techniques for improving properties of a light-emitting layer, such as crystallinity. For example, Patent Document 1 discloses that hydrogen is added to a semiconductor growth system during interruption of growth of well layers and barrier layers for suppressing segregation of In, whereby the crystallinity of the grown semiconductor is improved (see, paragraph [0006] of Patent Document 1).    Patent Document 1: Japanese Patent Application Laid-Open (kokai) No. 2010-141242
As described in Patent Document 1, segregation of In can be suppressed by adding hydrogen to a semiconductor growth system for forming a light-emitting layer. However, hydrogen sometimes removes In via an etching effect thereof. In such a case, the In concentration of a well layer included in the light-emitting layer varies. As a result, in some cases, the luminance of the light emitted by the light-emitting device decreases, and the wavelength of the emitted light is shifted.